1. Field of the Invention
The present invention relates generally to mounts or base assemblies for mounting dynamo-electric machines firmly on a flat mounting surface.
2. Description of the Known Art
Base assemblies which conform to an outer circumferential periphery of a dynamo-electric machine shell are known from, for example, U.S. Pat. Nos. 1,361,136 (Dec. 7, 1920) and 3,501,660 (Mar. 17, 1970) and Japanese Patent Document No. 59-89542 (May 23, 1984). The known assemblies are formed of sheet metal which is either welded to or press fitted against the exterior of the machine shell. In an arrangement disclosed in French Application No. 2,316,849 (Jan. 28, 1977) two interlocking sheet metal halves form a V, the upper ends of which are bolted to a motor. Opposite ends of the halves have openings to receive fastening elements to secure the assembly to a mounting surface.
The above known base assemblies are not, however, disclosed as being capable of allowing a machine shaft to be positioned at a selected one of two heights over the mounting surface, so as to comply with different industry standards, for example, those prescribed by the National Electric Manufacturers Association (NEMA) Publication No. MG1-1978, and those set out by International Electrotechnical Commission (IEC), Publication No. 72.
Specifically, although the dimensional standards prescribed by both the above organizations may be quite close to one another for a given machine of a certain power rating, it has been required to manufacture different base assemblies for the machines to conform to the machine casing or shell peripheries and, importantly, to support the shells a proper height over the mounting surface so that the axis of a rotor shaft of the machine will extend over the mounting surface at the height prescribed by the standard of interest.
Another problem arises in that, once the known sheet metal base assemblies are welded to the machine shell, it becomes difficult, if not impossible, to remove them from the machine in the event a different kind of mounting, e.g., a C-face or D-flange type end shield is to be substituted on the machine.